Personalism is an intellectual stance that emphasizes the importance of the human person. Personalism exists in many different versions, and this makes it somewhat difficult to define as a philosophical and theological movement. Friedrich Schleiermacher first used the term personalism (German: Personalismus) in print in 1799. One can trace the concept back to earlier thinkers in various parts of the world.

Writing in the Stanford Encyclopedia of Philosophy, Thomas D. Williams and Jan Olof Bengtsson cite a plurality of "schools" holding to a "personalist" ethic and "Weltanschauung", arguing:

Personalism exists in many different versions, and this makes it somewhat difficult to define as a philosophical and theological movement. Many philosophical schools have at their core one particular thinker or even one central work which serves as a canonical touchstone. Personalism is a more diffused and eclectic movement and has no such common reference point. It is, in point of fact, more proper to speak of many personalisms than one personalism. In 1947 Jacques Maritain could write that there are at least "a dozen personalist doctrines, which at times have nothing more in common than the word 'person.'" Moreover, because of their emphasis on the subjectivity of the person, some of the more important exponents of personalism have not undertaken systematic treatises of their theories.

It is perhaps more proper to speak of personalism as a "current" or a broader "worldview", since it represents more than one school or one doctrine while at the same time the most important forms of personalism do display some central and essential commonalities. Most important of the latter is the general affirmation of the centrality of the person for philosophical thought. Personalism posits ultimate reality and value in personhood – human as well as (at least for most personalists) divine. It emphasizes the significance, uniqueness and inviolability of the person, as well as the person's essentially relational or social dimension. The title "personalism" can therefore legitimately be applied to any school of thought that focuses on the centrality of persons and their unique status among beings in general, and personalists normally acknowledge the indirect contributions of a wide range of thinkers throughout the history of philosophy who did not regard themselves as personalists. Personalists believe that the person should be the ontological and epistemological starting point of philosophical reflection. Many are concerned to investigate the experience, the status, and the dignity of the human being as person, and regard this as the starting-point for all subsequent philosophical analysis.

— Thomas D. Williams

Thus, according to Williams, one ought to keep in mind that although there are many theorists and activists in the West adhering to the rubric of "personalism," their particular foci may not align with each other and, in fact, might even diverge considerably.

Nikolai Alexandrovich Berdyaev (1874–1948) was a Russian religious and political philosopher who emphasized human freedom, subjectivity and creativity.

In France, philosopher Emmanuel Mounier (1905–1950) was the leading proponent of personalism, around which he founded the review Esprit, which exists to this day. Under Jean-Marie Domenach's direction, it criticized the use of torture during the Algerian War. Personalism was seen as an alternative to both liberalism and Marxism, which respected human rights and the human personality without indulging in excessive collectivism. Mounier's personalism had an important influence in France, including in political movements, such as Marc Sangnier's Ligue de la jeune République (Young Republic League) founded in 1912.